Power Source Mode does not Change to ON (IG and ACC): Description
WARNING: This page is about a different car, the 2007 Lexus ES 350. However, it is still accessible from the selected car via links, so may be relevant.
When the engine switch is pushed with the electrical key in the cabin, the main body ECU receives signals to switch the power source mode.
HINT:
To allow use of the intelligent tester to inspect the push-button start function when the engine switch is off, repeat opening and closing any of the doors. Opening and closing a door establishes communication between the intelligent tester and the main body ECU. (Opening and closing a door can also be simulated by operating a door courtesy light switch.)